Pediatric bipolar disorder (PBD) is a spectrum of serious psychiatric disorders with considerable controversy surrounding its clinical presentation, course, and treatment response prior to puberty. Unfortunately there are substantial problems associated with accurately identifying these disorders in children. These difficulties stem from the overlap of the symptoms of PBD with other common conditions (such as ADHD, depression and conduct disorder) as well as the lack of prospective longitudinal studies of the differential symptomatology, treatment response and functioning of children selected for the hallmark feature of bipolarity, elevated symptoms of mania (ESM). There is a growing body of scientific evidence that a large number of children who are brought to psychiatric care have ESM. Some of these children meet strict DSM-IV criteria for the prototypic bipolar disorders, bipolar 1 (BP1) or bipolar 2 (BP2) disorder. However, a substantial number of children with ESM do not meet DSM criteria for either BP1 or BP2. Regardless of their working diagnosis at the time of assessment, children with ESM suffer from high degrees of psychopathology and from pronounced psychosocial dysfunction. Furthermore, the limited and dated follow-up data available suggests that many children with ESM do not develop bipolar disorders over time. Regrettably, very little is known about the phenomenology, course, or symptomatic evolution of youngsters who present with ESM. The "Longitudinal Assessment of Manic Symptoms" (LAMS) study is a collaborative, multi-site R01 that proposes to carefully investigate ESM in children and adolescents. The proposed project would be conducted at four sites over five years: Case Western Reserve University/University Hospitals of Cleveland (Case/UHC), Western Psychiatric Institute and Clinic (WPIC), Cincinnati Children's Hospital Medical Center/University of Cincinnati (CCHMC/UC), and Ohio State University. LAMS proposes the innovative step of screening a large sample of children who present for care with ESM, regardless of their clinical diagnoses, and carefully examining them both cross-sectionally and over time. LAMS will advance the field by providing the data necessary to develop valid, evidence-based criteria for a childhood-specific bipolar phenotype. The proposed research will also lend clarification to current controversies regarding the differential diagnosis between bipolar spectrum disorders and ADHD in children.